Refrigerating apparatus



Sept. 20, 1932. JKING 1,877,891

REFRIGERATING APPARATUS Filed May 29, 1951 J11. mvarg;

HI ATTORNEYS.

Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE JESSE G. KING, OFDAYTON, OHIO, ASSIGNOR '10 FRIGIDAIRE CORPORATION, 01 DAYTON,

' OHIO, A CORPORATION OF DELAWARE :anrmem'rme APPARATUS Applicationfiled Kay 29, 1931. Serial No. 541,000.

the valve is temporarily held open, from flowing into the outletthereof. Excess liquid re- 16 frlgerant upon entering the outlet of theof the evaporator, so as to receive thetemevaporator and the gaseousrefrigerant conduit leading therefrom causes frost to collect on thisconduit which frost will melt, when operation of the system againbecomes normal, and will flow on to the floor or walls of the buildingin which the system is installed, thus causing deterioration of thefloor and these walls.

The object of the present invention is to provide an evaporator of arefrigerating system with means whereby a temporary flow of an excessivequantity of liquid refrigerant to the evaporator is prevented fromentering'the outlet thereof.

Another object of the invention is to provide means whereby a temporaryflow of an excessive quantity of liquid refrigerant to an evaporator ofa refrigerating system will be readily vaporized to prevent the level ofliquid refrigerant maintained therein from rising above a predeterminedheight. In carrying out my invention I provide a trap or reservoircommunicating with the interior porary flow of excess liquid refrigerantthereto, which trap I dispose in the path of flow of the medium to be orbeing cooled by the evaporator so that rapid vaporization I expander ofthe excess liquid refrigerant occurs.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing, wherein a preferred form of the present invention is clearlyshown.

In the drawing: Fig. 1 is a vertical section through a portion of arefrigerator cabinet having an evaporator constructed in accordance withmy invention installed therein and o eratively connected with arefrigerant lique ying unit shown diagrammatically; and

Fig. 2 is an enlarged sectional view of my improved evaporator taken onthe lines 2-2 of Fi 1.

Ref erring to the drawing, Fig. 1 discloses a vertical section of aportion of a cabinet 10 illustrating the installation of an evaporatoror cooling unit 11 constructed according to my invention. The evaporator11 is.

supported within the cabinet 10 by brackets 12 and 13 attached to theinner lining 14 of the cabinet. The lining 14 of the cabinet 10 iscovered with insulation 15 and an outer framework or covering 16. AnL-shaped partition 18 provides a compartment 19 for the evaporator andhas openings 20 and 21 located therein for the circulation of airthrough compartment 19 for cooling the rest of the cabinet or foodstorage chamber 22 thereof. The bonnet 23 prevents any dripping ofcondensed moisture from the evaporator on to the food stored in thechamber 22 below the opening 21. The air within the compartment 19 uponbeing cooled by the cooling effect produced by t e evaporator is causedto circulate. The cold air circulates downwardly through the opening 21and into the food storage chamber 22 while the relative warmer air inchamber 22, upon being displaced by the air cooled by the evaporator,flows through the opening 20 and thence downwardly over the evaporator.

The evaporator 11 includes connections 25 and 26 adapted to be connectedto a refrigerant liquefying unit. I have shown t e evaporator 11connected to a refrigerant liquefying unit of thecompressor-condensertype which includes,a compressor 27, a condenser 28and a liquid refrigerant tank- 29. Refrigerant vapor is withdrawn fromthe evaporator 11 through a vapor or low pressure conduit 31 and isliquefied in the condenser 28 and returned to the evap orator 11 througha liquid or high pressure conduit 32. The compressor 27 is operated by amotor 33 controlled by an automatic switch 34 which may be actuated inresponse to the refrigerating demand, for example by 5. apressure-responsive device 36 connected to the low pressure conduit 31.It is obvious in systems of the type disclosed that thepressure-responsive device 36 which actuates the switch 34 forcontrolling the electric circuit W to the motor is adjusted to operatebetween certain pressure limits. Since pressures and temperatures of therefrigerant increase or decrease uniformly, it is apparent that thedevice 36 is adapted to maintain certain predetermined temperaturelimits' Within the evaporator of the system.

At the beginning of operation of the sys to as an off phase of a cycleof operation of the unit. Thus, it is apparent that while the system isin operation toproduce refrigeration, the refrigerant liquefying unit iscyclically operated and that each cycle thereof includes an one phaseand an off phase.

Referring now to Fig. 2, evaporator 11. comprises a header or receptacle40 forming a reservoir for liquid refrigerant, and.

a plurality of ducts 41 depending from the receptacle or header 40 forcirculating refrigerant to a pointmemote from the header. The liquidrefrigerant indicated at 42 is normally prevented from rising above thepredetermined level 43 by a valve 44 which con-;

trols a liquid refrigerant inlet opening 46 extending from theconnection 25 through an end plate 47. Valve 44 is actuated in responseto the liquid refrigerant level by a float 48. Float 48 is pivotallymounted as at 49 to a member 51 which is secured, in anysuitable manner,to an inwardly extending boss 52 formed on the-end plate 47 The liquidrefrigerant is supplied to the evaporator through inlet connection 25and the vapor orgaseous refrigerant is withdrawn through an outletopening or inwardly extending pipe 53, thence through the connection 26connected to the vapor conduit 31. 1 j

In refrigerating systems of the type disclosed employing a valve formaintaining a predetermined quantity or level of liquid refrigerant inthe evaporator thereof, it has been found that foreign particles in thesystern, which tend to circulate with the refrigerant, often gets caughtor stuck between the control valve and its seat, thus causing an. excessflow of liquid refrigerant to the evaporator. It is to be understoodthat this exoess flow of liquid refrigerant may occur only temporarilyor between one operating or on phase of the refrigerant liquefying unitand the succeeding on phase thereof. However, this temporary flow ofexcess liquid refrigerant into the evaporator has been found to besufiicient at times to raise the liquid level thereof in the evaporatorto such a height that upon the succeeding on phase of a cycle of therefrigerant liquefying unit, liquid refrigerant will be splashed by theboiling action thereof into the gaseous refrigerant outlet of theevaporator. This splashing of liquid refrigerant into the outlet of theevaporator causes evaporation thereof in the gaseous refrigerant returnconduit, leading from the outlet to the compressor of the unit,consequently a refrigerating effect is produced by the conduit'and frostcollects on the exterior thereof. In most installations of refrigeratingsystems of the type disclosed the gaseous refrigerant return conduit,leading from the evaporator to the refrigerant liquefying unit, has agreater portion of its length located exteriorly of the cabinet beingrefrigerated by the system. The collection of frost on the gaseousrefrigerant conduit of the system, while the valve controlling theingress of liquid refrigerant to the evaporator leaks temporarily, willmelt when the valve again maintains a perfect seat against the inletopening, to cause normal and proper flow of refrigerant to theevaporator,

and moisture created by the melting of the front will flow from theconduit.' This moisture upon flowing from the conduit dro s or flowsonto the floor or walls of the buil ing, in which the refrigeratorcabinet or the system is located, and causes deterioration thereof.

My invention is directed to a refrigerating system whereby temporarysplashing of liquid refrigerant into the outlet of the evap-- oratorthereof and, the gaseous refrigerant return conduit connected to theoutlet is prevented. This thereby prevents the collection oraccumulation of frost on the conduit and consequently deterioration ofthe floor or walls, in which the refrigerator cabinet or the system islocated, is prevented. I provide the evaporator of the system withconduit means or a trap, which is normally devoid or free of liquidrefrigerant, to receive excess I theevaporator does not splash liquidrefrigerant into the outlet thereof.

Referring again to Fig. 2 of the drawing, I have provided an evaporatorwith means for receiving excess liquid refrigerant entering theevaporator and isolating same out of .con-

tact with the main body of liquid refrigerant" in the evaporator whichmeans also causes rapid vaporization of the excess liquid refrigerant;This means includes a trap or conduit 'means 55 carried by or secured tothe header good'thermalcontact therewith. Trap 55 is adapted to belocated in the compartment 19 being, or to be, cooled by the evaporatorso that it is disposed in the vicinity of or adjacent the opening 20..For the purpose of 1llustrating my invention I have shown the trap orconduit means 55 as being connected to the rear wall of the header 40 ofthe evaporator 11 and extending outwardly therefrom so as to be disposedin thepath of relatively warm air entering the compartment 19 from thechamber 22 through the opening 20. It is thus apparent that the fins 57will absorb heat from the relatively warmer air flowing thereover andconduct this heat to the liquid refrigerant in the trap, if any ispresent therein, thereby causing rapid vaporization of the liquidrefrigerant.

During operation of the system, as previously described the compressor27 upon being operated withdraws gaseous refrigerant from the evaporator11 and reduces the pressure therein, thus causing more refrigerant toevaporate from the body of liquid thereof.

As liquid evaporates'it isobvious that the level 43 thereof withintheheader 40 will tend to .lower but the float 48 responsive to this levelalso moves downwardly, thus moving the valve 44 away from its seat. andpermitting the entrance of liquid refrigerant from the conduit 32 andconnection 25. If any particles of foreign material, tending tocirculate with the refrigerant in the system, should get caught orbecome stuck between the valve 44 and its seat during the period of timethe valve is open, the valve 44 will not entirely seal the liquidrefrigerant-inlet opening 46,

' after it has admitted the proper amount of liquid refrigerant to theevaporator. There fore liquid refrigerant continues to leak past thevalve 44 and raises the level 43 thereof in the header 40.. Thecompressor 27 is usually of such capacity that a small leak of liquidrefrigerant into the evaporator will not cause continuous operation" ofthe refrigerant liquefying unit, therefore thecompressor will reduce thepressure in the evaporator to the desired low limit and cause thepressure responsive device 36 to actuate the electric switch 34to stopthe motor 33 which drives the compressor 27. Upon the next succeedingoperating period of the compressor the valve will again open andordinarily such small particles caught between the valve and its seatwill be removed or flushed therefrom by the force of the incoming liquidrefrigerant to the evaporator. It is apparent therefore that suchleakage of liquid refrigerant past the valve occurs only-temporarily andbetween a few occasional complete cycles of the system only. Leaking ofliquid refrigerant past the valve 44 causes the liquid refrigerant level43 in the header 40 to rise to the opening or point of communication 56between the trap '55 and the header 40. Thereafter the excessivequantity of liquid refrigerant entering the evaporator flows -into thetrap where it is stored temporarily out of contact with the main body ofliquid refrigerant in the evaporator. Since the trap 55 is disposed inthe relatively warmer circulating air, rapid 'vaporizaton of the liquidrefrigerant received therein will occur. In this manner the level ofliquid refrigerant in the evaporator is prevented from rising andtherefore this level does not attain a sufficient abnormal heighttopermit boiling or evaporating refrigerant in-the evaporator to causesplashing of liquid refrigerant into the outlet thereof .during the timethe valve permits temporary leaks.

While I have described the system as circulating refrigerant only it isto be understood that it is usually necessary to lubricate operatingparts thereof with a lubricant or oil and it is well-known to thoseskilled in the art that an oil lighter in specific gracity than theliquid refrigerant can be used successfully. Some of this lubricanti maycirculate with liquid refrigerant to the evaporator and will separate bygravity from the liquid refrigerant in the evaporator and will rise tothe top surface thereof. Obviously this 111- bricant may flow into thetrap .or conduit means 55 of my improved evaporator without imp airingthe results desired to be ob tained by its use.- Such lubricant presentin the trap 55 will be displaced by the entrance of liquid refrigerantthereto which refrigerant is heavier than the lubricant and gravitatesto the bottom of the trap. 1 From the foregoing it is, apparent that Ihave provided a novel eva'poratorand consequently animprovedrefrigerating system when. operatively connected with such anevaporator. My improved evaporator insures that gaseous refrigerant onlywill enter the-outlet thereof at all times, thereby the collection or,accumulation of frost on the gaseous refrigerant return conduit leadingfrom the outlet of the-evaporator is eliminated. By eliminating thecollection offrost from the conduit during temporary abnormal conditionswithin the evaporator, I provide animprovedsystem which is 'capable ofoper:

ation over long periods of time without the danger 'of deteriorating'floors or walls 1n which the system islocated.

While the form of embodiment of the invention as herein disclosed,constitutes a pre- 7 ferred form, it is to be understood that otherforms might be adopted, all comlng within the scope of the claims whichfollow.

What is claimed is as follows: n 1. In a refrigerating system comprlslngn combination, an evaporator including a l quld refrigerant inletopening and a gaseous refrigerant outlet opening, meanscontrolling theingressof liquid refrigerant through said inlet opening-to saidevaporator and for normally preventing liquid refrigerant from risingabove a predetermined level therein, conduit means communicating withthe interlor of said evaporator and extending outwardlytherefrom, thepoint of communication of said conduit means with said evaporator beingdisposed in a plane between the plane of said outlet opening of saidevaporator and the liquid refrigerant level being mainta ned there- ,in,said conduit means being normally entirenormally preventing liquidrefrigerant from rising above a predetermined level therein, a trapcommunicating with the interior of said evaporator and extendingoutwardly therefrom, the point of communication of said trap with saidevaporator being disposed in a plane between the plane of said outletopening of said evaporator and the liquid refrigerant level beingmaintained therein, said trap being normally entirely free of liquidrefrigerant and arranged to receive liquid refrig erant rising above thenormal level maintained in saidevapo'rator by said first named means. r

3. In a refrigerating system comprising in combination an evaporatorincluding a liquid refrigerant inlet opening and a gaseous re-'frigerant outlet. opening, means controlling the ingress of liquidrefrlgerant through said inlet opening to said evaporator and fornormally preventing liquid refrigerant from rising abovea predeterminedlevel therein, a trap carried by said evaporator and commu'nicating withthe interior thereof, the point of communication of said trap with saidevaporator being disposed in a plane between the plane of said outletopening of said evaporator and the liquid refrigerant level beingmaintained therein, said trap being normally entirely free of liquidrefrigerant f and arranged, to receive; liquidfrefrigerant rising abovethemormal" level maintained in said evaporator by said first namedmeans.

4. Ina refrigerating system comprising in conibin'aton, an evaporatorincluding a liquid refrigerant inlet opening and a gaseous refrigerantoutlet opening, means controlling the ingress of liquid refrigerantthrough,

said inlet opening to 'saidevaporator andfor' normally preventing liquidrefrigerant from rjsingiabove a predetermined. level therein,

conduit means communicating with the interior of said evaporator andextending'outwardly therefrom, the point of communication ofsaid conduitmeans with said evaporatorbeingfdisposedin a plane between the plane ofsaid outletopening of said evaporator and theliquid refrigerant levelbeing maintained therein, said conduit meansbeing normally entirelyfreeof liquid refrigerant and arranged to receive liquid refrigerant risingabove thenormal level 'maintained in said evaporator by said first namedmeans, said conduit means beingalso arranged to insolateliquidrefrigerant received therein outof contact with the main bodythereof in W saidevaporator, and means on said conduit means to causeliquid refrigerant received i therein to vaporize more rapidly thanliquid refrigerant in the main portion of the evaporator;

v 5, In a refrigerating apparatus compris-k ing in combination, acabinet, an evaporator disposed in said vcabinet for cooling and causingthe circulation of air within said cabinet, said evaporator including aliquid refrigerant inlet opening and a gaseous refrig'erant outletopening, means controlling the ingress of liquid refrigerant throughsaid inlet opening to said evaporator, and for normally preventingliquid refrigerant from rising above a predetermined devel therein,

conduit means communicating with the interior of said evaporator andextending outwardly therefrom, the point of communica tion of saidconduit means with said evaporator being disposed in a plane between thef plane of said-outlet opening of said evaporator and the'liquidrefrigerant level gbeing maintained therein, said conduit means" beingnormally entirely free of liquid refrigerant and arranged toreceive-liquid refrigerant rising above the normal level maintained infsaid evaporator by said first named means, said conduit means beingdisposed in the path of air circulating within said cabinet and arrangedto isolate liquid refrigerant received therein out of contact with themain body thereof in said evaporator.

6. In a refrigerating apparatus comprising in combination, a cabinet, anevaporator disposed in said cabinet for cooling and causing thecirculation of air within said cabinet, said evaporator including aliquid refrigerant inlet opening and a gaseous refrigerant outletopening, means controlling the ingress of liquid refrigerant throughsaid inlet opening to said evaporator and for normally preventing liquidrefrigerant from rising above a predetermined level therein, a trapcommunicating with the interior of said evaporator and extendingoutwardly therefrom, the point of communication of saidtrap with saidevaporator being disposed in a plane between the plane of said outletopening of said evaporator and the liquid refrigerant level beingmaintained therein, said trap being normally entirely free of liquidrefrigerant and arranged to receive liquid refrigerant rising above thenormal level maintained in said evaporator by said first named means,said trap being disposed in the path of air circulating within saidcabinet.

7. In a refrigerating system comprising in combination, an evaporatorincluding a receptacle having a liquid refrigerant inlet opening and agaseous refrigerant outlet opening, means controlling the ingress ofliquid refrigerant'through said inlet opening to said receptacle and fornormally preventing liquid refrigerant from rising above a'predeterminedlevel therein, conduit means communicating with the interior of saidreceptacle and extending outwardly therefrom the point of communicationof atleast one 0 said conduit means with said receptacle being disposedin .a plane between the plane of said outlet opening of said receptacleand the liquid refrigerant level being maintained therein, the said oneof said conduit means being normally free of liquid refrigerant andarranged to receive liquid refrigerant rising above the normal levelmaintained in said receptacle by said first named means and said one ofsaid conduit means being also arranged to isolate liquid refrigerantreceived therein out of contact with the main body thereof in saidevaporator.

8. An evaporator of a refrigerating system comprising in combination, areservoir adapted to contain a. predetermined amount of liquidrefrigerant, means for preventing the accumulation of more than saidpredetermined amount of l1qu1d refrlgerant in said reservoir, said meanscomprising a receptacle having an o ening communicating with saidreservoir ad] acent the level of liquid refrigerant therein, saidreceptacle receiving liquid refrigerant from said reservoir in excess ofsaid predetermined amount and collecting same out of contact with liquidrefrigerant in the reservoir, a Wall of said receptacle being arrangedin the medium to be cooled by said evaporator to cause more rapidevaporation of refrigerant received therein, relative to evaporation ofrefrigerant in said reservoir, for normally maintaining said receptaclefree of liquid refrigerant.

1 9. An evaporator of a refrigerating system comprising in combination,a reservoir adapted to contain a predetermined amount of liquidrefrigerant, means for preventing theaccumulationof more than saidpredetermined amount of liquid refrigerant in said reservoir, said meanscomprising a receptacle having an opening communicating with saidreservoir adjacent the level of liquid refrigerant therein, saidreceptacle receiving liquid refrigerant from said reservoir in excess ofsaid predetermined amount and collecting same outof contact with liquidrefrigerant in the reservoir, and thermal conducting means associatedwith said receptacle and arranged in the medium to be cooled by saidevaporator to cause more rapid evaporation of refrigerant received insaid re' ceptacle, relative to evaporation of refrigerant in saidreservoir, for normally maintaining said receptacle free of liquidrefrigerant.

In testimony whereof I hereto afiix my signature.

JESSE G. KING.

